Noble Six. And Deliver Hope when Kat's arm is broken. Both of those get me every time. And those Mata Nui d*** Heretic Snipers. Me and my friends spent hours trying to kill those guys on NORMAL difficulty.

The scene in KotOR when you find out Bastilla has fallen to the Dark Side. She's been by your side every step of the way for most of the game, you (probably) are hoping to rescue her from Malak, and then, wham, she's evil.

That moment in Shadow of the Colossus when your horse flung you to safety as it fell down into a ravine, and also that moment when you realized that you weren't selflessly slaying great beasts to save your girlfriend, but that rather, you were murdering innocent creatures because you couldn't get over your girlfriend and a voice in your head told you it might bring her back to life.

And then there's the one game you would NEVER in a million years expect to have a depressing ending, Conker's Bad Fur Day, the game where you fight an opera singing monster made of poop and ride on a T-rex to bite a man's "big bone" off. That one totally hit me by surprise.